Leak-detector for gas



(No Model.)

I. M. ODONEL.

LEAK DETECTOR FOR GAS.

Patented Jan. 26, 1886.

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UNITED STATES PATENT OFFICE.

IRVIN M. ODONEL, OF ALLEGHENY, PENNSYLVANIA.

-LEAK-DETECTOR FOR GAS.

Application filed May 29, 1885.

To all whom) it may concern.-

Be it known that-I, IRvrN M. ODONEL. of the city of Allegheny, in the county of Allcgheny and State of Pennsylvania, have invented a new and useful Improvement in Leak-Detectors for Gas; and I do hereby declare the following to be a full, clear, and exact description thereof.

The object of my invention is to provide means for the detection of gas, and for indieating the same by an automatic alarm. The natural principle which I employ in my improved apparatus is that of the diffusion of gases. The physical law is that gases have tendencies to mix with each other, the ratios of which are inversely proportional to the square roots of their densities. Thus it is well known that if a gas be inclosed in a porous vessel of earthenware or other material which is surrounded by a denser gas, the lighter gas will escape more rapidly from the Vessel than the denser gas can enter it, and a partial vacuum will be produced in the vessel, which will continue until the gases with- 1n and without reach an equilibrium of density. On the other hand, if the vessel be surrounded by a lighter gas than is contained within it, the outer gas will diffuse itself into the vessel more rapidly than the denser gas can escape through the pores, and there will be a correspondingly greater pressure on the in side of the vessel than without until an equilibrium is restored, as above stated. I apply this principle to use by exposing a vessel having one or more porous sides inaplace which it is desired to protect from gas, and provide means for causing any increase or diminution of pressure therein to be exerted upon an indicator, which will give the desired alarm.

I will describe my invention by reference to the accompanying drawings, in which Figure 1 is a front view of my improved apparatus. Fig. 2 is a side elevation of the same, shown partly in section on the line 00 a; of Fig. 1.

Like letters and figures indicate like parts.

In the drawings, 2 represents a box or vessel, made in whole or in part of-plastcr-of paris or other porous material. At its base is an opening which is covered by an elastic diaphragm, 3, of thin rubber, sheepskin, or other material. A wire, 4, is connected with this diaphragm, and is forked, one branch, 6, eX-

Serial No. 167,025.

EATION forming part of Letters Patent No. 33 L890, dated January 26, 1886.

(No model.)

an nunciator. If, now, the vessel 2, which normally is filled with air, be placed in the presence of hydro-carbon or similar light gas, the latter will immediately penetrate the pores of the plaster and create a pressure upon the diaphragm 3. The resulting depression of the diaphragm will push the wire 7 into the mercu ry of the cup 8, thereby connecting the wires NS, completing the electric circuit, and cansing the annunciator to give the proper alarm. The weight of the wires 4, 6, and 7 may conveniently be made such that when the diaphragm has descended it will not be withdrawn unless a pressure be applied from the outside upon it. The consequence is that when the inflow of gas has caused the wire fork to descend and give the alarm it will remain in the mercury and ring the alarm-bell continuously, even after equilibrium has been restored between the surrounding and inclosed gases. W'hen, however, the gas outside becomes denser than that in the vessel, either by cessation of a leak or other removal of the lighter gas, a vacuum in the vessel will be caused by the escape of its light contents, and there will be a resulting uplifting of the diaph ragm 3. This will raise the wire 7 from the mercury in the cup 8, thereby breaking the circuit and causing the alarm-bell to cease ringing. The advantage of this arrangement is that it will not only give warning ofthe presence of gas, but will also continue to give the alarm until the gas be removed.

Constructed as above described, the leakdetector is very simple and effective in its operation.

The diaphragm may be made so delicate as to indicate the presence of a very small proportion of hydrocarbon gas, a much less amount than is necessary to make an explosive when mixed with air.

The number of destructive accidents which have resulted from the accumulation of natural gas in the cellars and rooms of houses movement of the diaphragm may thus be'exceedingly magnified at the end lever or wheel of the series, and when the latter is arranged to make contact with an electric circuit will sound the alarm on occurrence of an almost imperceptible or very gradual addition of gas.

It will be understood that I do not desire to limit myself to the formof the vessel 2, nor to its exact construction and connection with the alarm-bell herein shown.

be near the ceiling of a room, and for heavier 3 5 gases near the floor.

I do not desire to claim, broadly, a vessel having minute passages for the diffusion of gas in combination with an annunciator for indicating changes in the pressure of the gase- 40 one contents of the vessel; but

What I claim as my invention, and desire to secure by Letters Patent, is-

1. In a gas-detector, the combination of a vessel having minute passages for the diffu sion of gas, a diaphragm capable of expan sion and retraction with the varying pressure of the gaseous contents of the vessel, and an annunciator for indicating such varying pressure, said annunciator being connected with the diaphragm and capable of operation by the movements thereof, substantially as and for the purposes described.

2. In a gasdetector, the combination of a vessel provided with minute passages for the diffusion of gas, a diaphragm capable of ex pansion and retraction with varying pressure of the gaseous contents of the vessel, an electrio circuit capable of being made and broken by movement of the diaphragm, and an annunciator operated by said circuit, substantially as and for the purposes described.

In testimony whereof I have hereunto set my hand this 12th day of May, A. D. 18 85.

IRVIN M. ODONEL.

Witnesses:

THOMAS W. BAKEWELL, J NO. K. SMITH. 

